GTA
All Springer/NP/PCP Air Gun Discussion General => European/Asian Air Gun Gates => German AirGun Gate => Topic started by: HectorMedina on January 23, 2019, 01:58:23 PM
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Recoil-less Spring-Piston Airgun?
Ideas, comments, and pro-positive suggestions welcome.
TIA!
HM
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It depends.
My daughter has a Giss-action air pistol that she loves. It is old and I don't even know who made it!
My case, probably to play with - but that is my standard answer for technology with an interesting name.
Dave
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Depending on power level...
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Recoil-less Spring-Piston Airgun?
Ideas, comments, and pro-positive suggestions welcome.
TIA!
No not me! I am not going to spend that kind of money on any AG. That’s just me!
HM
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I would have to say no. $800 is too deep into PCP territory. I'd probably shoot better with a Skyhawk anyways.
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IMO it would have to be super accurate, provide plenty of power and have top notch fit and finish. There are some fine rifles already on the market for $6-800, AA TX200 for example. If it's low power it wont sell as you can buy a very nice FWB 300, 600 series or possibly a Diana 75 for less than $800. While low powered these rifles are hole in hole accurate, the machining, fit/finish and engineering are still top notch thirty to fifty years later.
Having said that I'm a springer guy and would spend $800 on a spring rifle that had the qualities I mentioned long before I ever considered a PCP.
My $.02, Justin.
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So many variables!
I have 3 giss rifles, two of which are off for professional rebuild. When said and done, I’ll have a great deal of money into these rifles. So, in a way, I’ve spent nearly that much on older versions of the giss system. The giss system is like no other spring rifle I’ve ever shot. It is a marvel of ingenuity. I can only imagine what a modern interpretation would be like. I am very intrigued by the thought of a current production one. That being said, it comes down to the variables. For my 800 donuts, it would have to be beautiful, capable of producing 12ish FPE, have a lefty compliant configuration, and not take a rocket surgeon to change springs and seals. I would rather it not look like the quintessential boring sporter but have a crossover target/hunter look with vertical grip, adjustable comb, and stippling. It should be both iron sight and scope friendly and sent to me immediately for testing ;D. Above all, it should be breathtakingly accurate.
Perhaps I ask too much?
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I am very intrigued by the thought of a current production one. That being said, it comes down to the variables. For my 800 donuts, it would have to be beautiful, capable of producing 12ish FPE, have a lefty compliant configuration, and not take a rocket surgeon to change springs and seals. I would rather it not look like the quintessential boring sporter but have a crossover target/hunter look with vertical grip, adjustable comb, and stippling. It should be both iron sight and scope friendly and sent to me immediately for testing ;D. Above all, it should be breathtakingly accurate.
Perhaps I ask too much?
+1 ...except for that lefty part :D
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So many variables!
I have 3 giss rifles, two of which are off for professional rebuild. When said and done, I’ll have a great deal of money into these rifles. So, in a way, I’ve spent nearly that much on older versions of the giss system. The giss system is like no other spring rifle I’ve ever shot. It is a marvel of ingenuity. I can only imagine what a modern interpretation would be like. I am very intrigued by the thought of a current production one. That being said, it comes down to the variables. For my 800 donuts, it would have to be beautiful, capable of producing 12ish FPE, have a lefty compliant configuration, and not take a rocket surgeon to change springs and seals. I would rather it not look like the quintessential boring sporter but have a crossover target/hunter look with vertical grip, adjustable comb, and stippling. It should be both iron sight and scope friendly and sent to me immediately for testing ;D. Above all, it should be breathtakingly accurate.
Perhaps I ask too much?
No Higgy;
Your RIGHT ON THE MONEY!
;-)
The original 1956 patent, contemplated opposing pistons running INTO each other. The implementation was done with a bolt action on top and a vertical transfer port ¿Sounds familiar?
When the first prototypes were built, the problem was TOO MUCH power.
So, halve the swept volume and you get the 5.5 ft-lbs that are needed. One piston does the compression, the other does nothing except cancel inertia. Simple.
Just an idea we're toying about, but if the market responds . . .
The level of advancement in materials, methods of manufacturing, and knowledge about what really happens inside an airgun are way ahead of the wildest dreams Herr Giss could have ever had. In the 60's the gun was WAY AHEAD of its time, but ¿Now? THAT is the question.
Anyway, thanks for your answers and hopefully there will be a few more pronouncements with this little extra information.
Keep well and shoot straight!
HM
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No
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Yes.
If it is as hold-insensitive as a PCP.
If it comes in a synthetic bullpup stock, max 29" long.
If it has at least 25FPE with a .22 JSB 16gr.
In fact, I'd buy it tonight!!
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Maybe.
The physics and math you deal with are way beyond me but if "recoilless", how can there be "too much power". Moreover, a new 5.5 ft/lbs rifle seems to be a product in search of a very small market since used and very well used FWB 300s are still available for $600 or so, as are new low cost 10 meter rifles like the Air Force Edge, Crossman Challenger, and Air Arms T200.
Moreover, the sterling T16 seems to have the energy issue solved (https://www.youtube.com/watch?v=Tw4IVzpu7Kg (https://www.youtube.com/watch?v=Tw4IVzpu7Kg)) but then again, $2,000 U.S. and no official word on launch may mean we'll never see it released.
Note that personally, I'd pay PCP prices for a 12 ft/lb or higher energy spring piston rifle that could go head to head with similarly powered PCP rifles. Unfortunately, I'm contrary by nature so marketing gurus looking for profitable ideas need to stay away from me.
But wait!! Let us imagine a dual purpose "Recoil-less Spring-Piston Airgun". An air rifle that can be used legally for 10 meters in the Sportsman class, but can also be used in FT or Benchrest. For example, flip a port valve gate one way and excess air from one piston is exhausted for a 5.5 ft/lbs rifle. Alternatively, flip the gate valve the other way to direct air into the transfer port for a 12 ft/lbs airgun. Again,most math and physics are beyond me so I'm not sure what is, or is not, possible. In any event, as part of the contrarian market I would purchase such a beauty and would pay more than $800 for such a wonder. In fact, I'd pay $1000 to $2000 (or more) for a benchrest spring piston 25 meter rifle that is a PCP killer.
Oh and a big pet peeve is trigger pull. I don't care how crisp the trigger break may be, if is the pull required is more than one or two pounds you can keep the rifle. Safe, yes; but not heavy.
Please let me know when I can put a few thousand rounds through a "leased" pre-production prototype of my ideal wonder gun?
Best wishes.
The other Mark B.
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Yes. With some conditions. First, needs to do about 12fpe. Second, fit and finish worthy of an $800 springer. I'm talking FWB Sport, TX200, or HW97/77 fit and finish, not typical RWS/Diana fit and finish. I don't like painted metal like the Diana guns have. Not do I like the stamped metal parts common on the Diana guns. I'd like to see finely blued metal and laminate and/or Walnut options too, for maybe some more money.
I think a nicely done beech stock with finely blued metal with a recoiless GISS system that puts out 12fpe for $800 would be a hit. I think upgrades to walnut/laminate stocks for another couple hundred bucks would sell too, not as many but if I'm spending that kind of money I'd pay another $200 for a laminate or Walnut stock.
Don't get me wrong, you make a recoiless springer in the $800 range that does 12fpe and is nicer than typical Diana and the only option is beech stock...... I'll buy it even though it has a beech stock. Get Minnelli involved-they can make a beech stock look pretty decent.
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Yes. With some conditions. First, needs to do about 12fpe. Second, fit and finish worthy of an $800 springer. I'm talking FWB Sport, TX200, or HW97/77 fit and finish, not typical RWS/Diana fit and finish. I don't like painted metal like the Diana guns have. Not do I like the stamped metal parts common on the Diana guns. I'd like to see finely blued metal and laminate and/or Walnut options too, for maybe some more money.
I think a nicely done beech stock with finely blued metal with a recoiless GISS system that puts out 12fpe for $800 would be a hit. I think upgrades to walnut/laminate stocks for another couple hundred bucks would sell too, not as many but if I'm spending that kind of money I'd pay another $200 for a laminate or Walnut stock.
Don't get me wrong, you make a recoiless springer in the $800 range that does 12fpe and is nicer than typical Diana and the only option is beech stock...... I'll buy it even though it has a beech stock. Get Minnelli involved-they can make a beech stock look pretty decent.
My thoughts exactly. Would gladly pay $800 for such a springer.
R
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¡ Put me down as very interested !
Mitch
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I would spend that much, maybe more. I love springers. Fit and finish comparable to HW/AA, 12 ftlbs min up to 15 ftlbs max, weight under 9lbs.
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I would buy a rifle at that price point. My rws54 tuned cost more than that. It would have to be though no more than 8.5 pounds as that is my main problem with the air king
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Absolutely. Minimum 12 fpe though. That Sterling T16 is interesting- using gas rams... Very interesting!
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Yes 12 fpe accurate light enough to hunt with makes NO Sound or Spring twang.
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Got my interest also, 12fpe under 9 pounds.
Mike
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Being an original owner of a DIANA 75HV GISS 10 meter rifle .... When purchased circa @ 1981 was nearing 700.00
Even then the guns got a lot of stamp steel spot welded parts & pieces that when viewed side by side to say an FWB 300 is crude and unrefined. yet in shooting is like magic !! being so smooth and virtually recoiless having a trigger that is simply AWESOME !!!
Now here some 40 years later could such a gun be made again for nearly the same coin .... WOW, nice hat trick if it could. add to it being of greater power and a more practical air weapon to own & use as a sporting arm ... yea you got my attention !
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I want one, maybe 2?
In a heartbeat. 8)
-Y
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If you have ever shot one you would know. ;)
-Y
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If it has PCP power level (+25 fpe), in .22 or .25 and totaly recoilless, why not?
I don't have any PCPs, I'm sometimes thinking about it. But I don't like the idea you need a bottle or a pump and taking a quarter of an hour for filling it... I'm not talking about 100+ fpe where hand pumping will need an hour or more for 30 shots (or less) ! lol.
I really would love the FX Boss, but the price and half liter bottle hum...
I love the idea of a self powered rifle, all in one, that's why I like more springers. The only drawbacks are, one shot, limited power and not recoilless for high power / long range (80-100 yds).
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Thanks, my friends!
All your opinions are extremely interesting and valid.
At present it is just an idea we're toying with. We will have a bunch of meetings at IWA and after, and then we will know better if this will become a project for 2020-2021, or not.
I am, personally, not too inclined to the "jack of all trades, master of none" thing. I do understand the need to have 12 ft-lbs as a base power point. And then have a 5.5 ft-lbs version for those that do not want to bother with PCP's for Match Style shooting, nor do they want to go to the heavy cocking forces of the SSP's. But there are ways where almost the same rifle can produce the two different power levels, however the changes are at the heart of the gun (and it is not only the springs), so people wanting to do two styles would have to get two guns. In the end it is probably for the better, because the stock's dimensions and shapes can be so different between games that it is not only the powerplant what you need to worry about.
In spring-piston guns, weight and power go together. I do not see a technical problem getting 12 ft-lbs out of a 9 lbs gun. Getting 25 . . . that is wishful thinking. But maybe 14-16 is doable and it is the region where good hunting pellets in 0.177" are most accurate anyway.
The methods of old were what they were. Modern methods should allow us to make properly all the parts. PERSONALLY, I like the durability and corrosion resistance of the ceramic matte finish (not a paint) better than the polished blued steel, but I understand that aesthetics are personal things. That is a relatively minor point.
And yes, Minelli would definitely be involved if we go forwards, LOL!
Again, thanks my friends, thanks for enlightening us!
Keep well and shoot straight!
HM
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The D54/56 has already 22+ fpe and is "recoil free". If weight is not a concern it's possible indeed. Yep 14-16 seems quite interesting. Would it be the same principle as a Whiscombe? This guy was just a genius, but it's such a sensible mechanic and totaly out of price. Too bad it hasn't been more exploited and no more made.
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IVe got a D75 with that system in it.
Id buy another one, but now that Hector has mentioned it, I'll wait and see what that group is up to.....
Ill echo the 12 ft lbs request, and my biggest complaint with the D75 is the lack of stock adjustments. My SSP Anschutz SuperAirre 2002 has what I consider stock perfection, at least ergonomically......
synthetic would be fine as long as I can fit it and adjust it to fit......
ANd I'll also volunteer to test it in the high montana alpine deserts and snowfields...... 8)
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Recoil-less Spring-Piston Airgun?
Ideas, comments, and pro-positive suggestions welcome.
TIA!
HM
I would love to try one out. As for price? For the right gun, yes.
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The D54/56 has already 22+ fpe and is "recoil free". If weight is not a concern it's possible indeed. Yep 14-16 seems quite interesting. Would it be the same principle as a Whiscombe? This guy was just a genius, but it's such a sensible mechanic and totaly out of price. Too bad it hasn't been more exploited and no more made.
Eric;
The Giss was patented in 1956 by Kurt Giss and Mayer & Grammelspacher (DIANA), John Whiscombe started making airguns in the late 80's and 90's, last guns made were probably around year 2K.
Whiscombe used EXACTLY the Giss mechanism, but he inserted a ratchet mechanism to allow for multiple strokes cocking.
Whiscombes are notoriously temperature sensitive, that is why you do not see them much in FT (I only know of two that have competed in the World's with them) and they usually bring problems along the three days of competition due to their complexity.
The sled patent was also a DIANA original patent. FWB licensed it for their 300's series. Anschütz followed a different route. Diana used the Giss for Match airguns until it was replaced by the SSP (DIANA 100). After that, DIANA only made KK Match guns under special order.
Anyway, it is just an idea we're toying around.
Keep well and shoot straight!
HM
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Could a modern sled type action be made a little cheaper than the Giss system? The used market seems to favor the FWB300 over the Diana 60's and 75's, even though the FWB 300 doesn't work as well above the typical 10M energy. (9 FPE?)
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There was a guy in the UK a few years ago who made a recoilless spring gun, cancelling springs if I remember.
He was trying to get funding to go into production. Guess he never got it. :-\
-Y
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Honestly,
I would just be happy if my Diana 54 air king was available in a synthetic stock. Even a pound off would make a difference.
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Honestly,
I would just be happy if my Diana 54 air king was available in a synthetic stock. Even a pound off would make a difference.
I’d be interested in this idea as well. A lighter 54 sounds great, assuming that the current weight doesn’t provide the majority of the recoil dampening performance and the sled is doing its work.
-Marty
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A lighter 54 would be great to have. My 300S is at 5fpe, the 54 in .177 is about 17, the 54 in 20 is about 20. Each serves up dead chipmunks whenever the need arises. All shoot well. The 54s with scopes mounted are around 12lb each.
The comment about some of the recoil reduction being from the stock weight? I don't think so, as I shoot a lot off a bench and don't see/feel any significant movement. Actually when I do my followthrough properly (about half the time?) the crosshairs end up exactly on the center of the bull and the pellet does too.
My interest in the Giss system would be to see if I could get even better accuracy than I already have. I could move over to PCP guns but just don't need the additional pile of toys in my gun room!! I only have so many corners to fill!!!
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Honestly,
I would just be happy if my Diana 54 air king was available in a synthetic stock. Even a pound off would make a difference.
Ahhhh!, but that is ANOTHER project, LOL!
You'll hear more about this after IWA.
;-)
HM
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I haven't weighed them separately but think most of the mass is metal not wood. I'll take the stocks off and weigh each piece and report back in couple days.
I switched a 30/06 from wood to synthetic a couple years ago. The negative was a move in the center of mass from my hand to definitely front heavy. Weight reduction was about 1lb.
Maybe not such a neat idea????
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Two more comments to add. First, a 12 ft/lbs (+) rifle should have either a anschultz or a picatinney rail if for no other reason than to hang a removable sling stud. I can however, foresee hunters wanting to hang a bi-pod or set of sticks off the front as well. I personally would like to mount a adapter block that would sit within a front rest.
Any rail should be long enough so that an attached device can be positioned at the proper balance point for the rifle and attachment.
Second, the bottom of the buttstock should be parallel to the barrel so that the muzzle will not rise when a rear sand bag is being adjusted under the rifle.
Best wishes.
The other Mark B.
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Hector,
I will be interested if the rifle is accurate (30 shots inside 25mm at 50m) and consistent (temperature insensitive). I do not mind a heavy rifle but it needs to be well balanced - not front heavy. A field target stock would be an option of course. It would have, adjustable cheek piece, thumb up pistol grip and safety position. A fat (tall) forearm belly for shooting off the knee and standing.
Regards,
Leo
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Hector,
I like "springers" because they are "always ready". I appreciate the lack of vibration from PCPs, but like "simple". So, a springer with the shot cycle of a pneumatic interests me:
Dual opposing pistons, with only one "active", seems like paying for and carting the weight of a 5 liter V8, running always on only 4 cylinders.
If you want a low power version of a dual opposing piston rifle, could you achieve that by having two sears? A shorter stroke for 5.5 ft.lb, and a longer one for close to 12? That way, the user gets to choose what is most useful for their immediate applicable. An extra sear slot in each piston won't add a lot of cost...
Regardless of power, unless I am shooting off a bench or prone, weight and balance are very important to me. Ideally, 6 to 7 lb; and shorter than 42"; although feel and balance are more important. An 8+lb weight, shooting at only 5.5 ft.lb sounds like a dedicated target rifle. I prefer a bit more power, configured as a sporter.
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I got to shoot a John Whiscombe air rifle last year at a meet. There were only a few hundred made and from what i read, there was a guy who bought up about 100 of them.
It takes two strokes of the lever to cock it and the opposing pistons work opposite of each other and come together in the middle to push the air through a port like in a PCP.
There is absolutely no recoil, but again from reading, you never want to accidentally not put a pellet in the breech or the gun may go into self destruction.
Frome what I was told, the gun I shot was sold to the owner for $7000, but before the word "crazy" comes up, if his gun ever failed, he could probably get his money back in spare parts if he had to.
In this design, the opposing pistons both work to push air, not just cancel out vibration and recoil.
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An SSP rifle does not have to be hard to cock. Here are some ideas I am developing right now:
https://www.gatewaytoairguns.org/GTA/index.php?topic=153749.msg155692324#msg155692324 (https://www.gatewaytoairguns.org/GTA/index.php?topic=153749.msg155692324#msg155692324)
An underlever that uses similar linkages would enable a more rigid (accurate) barrel, and a higher cocking force (for 12 ft.lb) to be tolerated, ergonomically speaking.
Certainly, a 5.5 ft.lb SSP rifle that cocks easily should be relatively easy to produce. I estimate a peak cocking force of less than 15 lb for that, using the type of variable leverage linkages discussed at the above link; and this one: https://www.gatewaytoairguns.org/GTA/index.php?topic=153475.msg155689447#msg155689447 (https://www.gatewaytoairguns.org/GTA/index.php?topic=153475.msg155689447#msg155689447)
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Thanks for your continued interest!
M Bouchard.- I get your dedication to BR, but the entry point would be a basic, sporter model. Specialized stocks to come after.
Rails above and below will be added, depending on the final configuration we agree on. IF it gets done, and IF we come to a Synthetic stock, Picatinny rails for a number of accessories can be molded into the stock, so that is a no brainer.
Subscriber.- The ORGINAL DIANA Giss guns used only one piston to compress air because it was a need at the time. We tend to forget that in 1956, WWII had been over barely 11 years. DIANA could NOT make DIANA airguns for sale outside Germany, the complete company having been assigned to the Brits as "War reparations", and that the brand was only officially recovered after Millbro went bust.
Regarding your sliding fulcrum points, it is an idea we not only have been working on, but have bought a Patent about. We MAY bring it out if all the tests perform well.
BUT, it is not the only way. My own CCA WFTF D54 guns take 22 lbs of cocking force for an output up to 14 ft-lbs. So, in the spring gun world there are still efficiencies to be had, where the SSP's have pretty much reached a dead end. Again, in other words to make it clear: I agree with you, SSP's do NOT HAVE to be hard to cock, but the truth is that all of them are. Good luck with your implementation of the concept and, by all means, keep us posted, I have a direct order from our CEO to look for practical, great, ideas we can turn into products.
Leo.- I fully agree with you. With the caveat that I need to center my attention on that narrow definition that will make this a POSSIBILITY. Getting the perfect design in the perfect stock, even at the perfect price is meaningless if the gun then becomes such a a narrow appeal as to make the project unfeasible/impossible.
One of my first real-life experiences in work-life came from a Dutch boss of very little words I had. When I didn't deliver on a project because I kept "perfecting" the solution, he came to me, looked me in the eye and said: "Son, DONE is better than PERFECT".
Again, thanks for all your opinions and shows of interest. With over 2,500 shows of interest over three days just in the US and in two fora, I think that we have shown that the market may be there for the right machine.
What follows next is getting the "powers that be" at company, and group level, to agree to a path to develop further the ideas.
Thanks again, keep well and shoot straight!
HM
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Hector,
Thanks for your detailed reply.
Would it be rude to inquire the name of your company? How does one apply for a job there :)
I fully get that spring air rifles are more efficient than SSPs. That for higher FPE applications, the "springer" (adiabatic compression) efficiency advantage makes for a smaller, potentially lighter, and lighter cocking airgun.
So, if optimizing springer efficiency is the business path, you may already be implementing some of the ideas expressed below:
I recently bought two cheap refurb Gamo Big Cat gas-ram "springers" to splice together. My goal is a .22 "Frankenrifle" that delivers PCP level FPE, without exceeding 30 lb peak cocking force. Cocking would probably be done in two steps; or with a windlass, like a crossbow...
The plan is to cut off the barrel hinges and mount the two cylinders face to face. Then, have a TP in the middle with a Marauder style breech and barrel on top. I may replace the gas springs with steel (oh the vibration). This would be in order to use the space inside each piston ID to house an attached steel tube, holding tungsten shot. The OD of the inner steel tubes become spring guides.
The reason for the above is that springers loose efficiency in the form of piston bounce: Doubling up the swept volume will tend to make that bounce much worse (worst, if we assume the same caliber as the single power unit had).
The combined piston velocity will also make the air pressure spike much quicker and much higher; possibly to the point of blowing the pellet skirt up in a ridiculous manner. So, by adding some weight to the pistons to slow down their end of stroke velocity a little, and by disconnecting the mass in the form of a shower of tungsten pellets, the efficiency robbing piston bounce can be greatly reduced. This, while the two "heavy" pistons cancel each other's inertia.
Tungsten shot should be more gentle as a "deadblow hammer", than a single tungsten slug per piston. However, tungsten slugs with very light o-ring friction to hold them against gravity may behave in a more predictable manner, for the best vibration cancellation.
I can also see how ramming the air into a small "plenum" leading to the TP could help: Such a plenum would have a volume of perhaps one percent of the combined piston swept volume: The effect would be to reduce the peak air pressure to a level the pellets can handle. And, in combination with a reed valve at the entrance of this little plenum, restore efficiency otherwise lost, by preventing air from back-flowing, that would normally follow the bouncing pistons.
If this were a ground up design, I would consider making the bulk of the receiver tubing from aluminum. Using steel inserts for wear and to handle high pressure air only where such loads exist. As it is, just the receivers of the two Gamos would weight over 8 lb. That is OK for a testbed, but would add up to a 12 lb wood stocked rifle. Just the barrel-less powerplant would already exceed my preferred weight point for a sporter.
Airguns are a hobby for me. If I were in the business, I would not be sharing the above on an open forum. Not that I assume to have actually suggested anything you haven't heard before, or though of yourself. As the holder of over a dozen US patents, I know that virtually any "new idea" I come up with has been thought of before. Rather than disappointment, I see that as validation :)
EDIT: I found you at Connecticut Custom Airguns. I am sure people pester you for a job all the time. How many try to sell you product ideas, or do incidental consulting?
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Hector,
Thanks for your detailed reply.
Would it be rude to inquire the name of your company? How does one apply for a job there :)
I fully get that spring air rifles are more efficient than SSPs. That for higher FPE applications, the "springer" (adiabatic compression) efficiency advantage makes for a smaller, potentially lighter, and lighter cocking airgun.
So, if optimizing springer efficiency is the business path, you may already be implementing some of the ideas expressed below:
I recently bought two cheap refurb Gamo Big Cat gas-ram "springers". The plan is to cut off the barrel hinges and mount the two cylinders face to face. Then, have a TP in the middle with a Marauder style breech and barrel on top. I may replace the gas springs with steel (oh the vibration). This would be in order to use the space inside each piston ID to house an attached steel tube, holding tungsten shot. The OD of the inner steel tubes become spring guides.
The reason for the above is that springers loose efficiency in the form of piston bounce: Doubling up the swept volume will tend to make that bounce much worse (worst, if we assume the same caliber as the single power unit had).
The combined piston velocity will also make the air pressure spike much quicker and much higher; possibly to the point of blowing the pellet skirt up in a ridiculous manner. So, by adding some weight to the pistons to slow down their end of stroke velocity a little, and by disconnecting the mass in the form of a shower of tungsten pellets, the efficiency robbing piston bounce can be greatly reduced. This, while the two "heavy" pistons cancel each other's inertia.
Tungsten shot should be more gentle as a "deadblow hammer", than a single tungsten slug per piston. However, tungsten slugs with very light o-ring friction to hold them against gravity may behave in a more predictable manner, for the best vibration cancellation.
I can also see how ramming the air into a small "plenum" leading to the TP could help: Such a plenum would have a volume perhaps one or two percent of the combined piston swept volume: The effect would be to reduce the peak air pressure to a level the pellets can handle. And, in combination with a reed valve at the entrance of this little plenum, restore efficiency otherwise lost, by preventing air from back-flowing, that would normally follow the bouncing pistons.
If this were a ground up design, I would consider making the bulk of the receiver tubing from aluminum. Using steel inserts for wear and to handle high pressure air only where such loads exist. As it is, just the receivers of the two Gamos would weight over 8 lb. That is OK for a testbed, but would add up to a 12 lb wood stocked rifle. And that is twice as much as the lower target weight point for a sporter. Now, my goal with such a Frankenstein is .22 PCP level FPE, without exceeding 30 lb peak cocking force; probably done in two steps; or with a windlass, like a crossbow...
Airguns are a hobby for me. If I were in the business, I would not be sharing the above. Not that I assume to have actually suggested anything you haven't heard before, or though of yourself. As the holder of over a dozen US patents, I know that virtually any "new idea" I come up with has been thought of before. Rather than disappointment, I see that as validation :)
Build it and they will come. 8) ;)
Start with a prototype, proof of concept model.
I have solved all of the world problems either sitting on the can or in a bar. ;) :-[
-Y
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Hector,
Thanks for your detailed reply.
Would it be rude to inquire the name of your company? How does one apply for a job there :)
I fully get that spring air rifles are more efficient than SSPs. That for higher FPE applications, the "springer" (adiabatic compression) efficiency advantage makes for a smaller, potentially lighter, and lighter cocking airgun.
So, if optimizing springer efficiency is the business path, you may already be implementing some of the ideas expressed below:
I recently bought two cheap refurb Gamo Big Cat gas-ram "springers" to splice together. My goal is a .22 "Frankenrifle" that delivers PCP level FPE, without exceeding 30 lb peak cocking force. Cocking would probably be done in two steps; or with a windlass, like a crossbow...
The plan is to cut off the barrel hinges and mount the two cylinders face to face. Then, have a TP in the middle with a Marauder style breech and barrel on top. I may replace the gas springs with steel (oh the vibration). This would be in order to use the space inside each piston ID to house an attached steel tube, holding tungsten shot. The OD of the inner steel tubes become spring guides.
The reason for the above is that springers loose efficiency in the form of piston bounce: Doubling up the swept volume will tend to make that bounce much worse (worst, if we assume the same caliber as the single power unit had).
The combined piston velocity will also make the air pressure spike much quicker and much higher; possibly to the point of blowing the pellet skirt up in a ridiculous manner. So, by adding some weight to the pistons to slow down their end of stroke velocity a little, and by disconnecting the mass in the form of a shower of tungsten pellets, the efficiency robbing piston bounce can be greatly reduced. This, while the two "heavy" pistons cancel each other's inertia.
Tungsten shot should be more gentle as a "deadblow hammer", than a single tungsten slug per piston. However, tungsten slugs with very light o-ring friction to hold them against gravity may behave in a more predictable manner, for the best vibration cancellation.
I can also see how ramming the air into a small "plenum" leading to the TP could help: Such a plenum would have a volume of perhaps one percent of the combined piston swept volume: The effect would be to reduce the peak air pressure to a level the pellets can handle. And, in combination with a reed valve at the entrance of this little plenum, restore efficiency otherwise lost, by preventing air from back-flowing, that would normally follow the bouncing pistons.
If this were a ground up design, I would consider making the bulk of the receiver tubing from aluminum. Using steel inserts for wear and to handle high pressure air only where such loads exist. As it is, just the receivers of the two Gamos would weight over 8 lb. That is OK for a testbed, but would add up to a 12 lb wood stocked rifle. Just the barrel-less powerplant would already exceed my preferred weight point for a sporter.
Airguns are a hobby for me. If I were in the business, I would not be sharing the above on an open forum. Not that I assume to have actually suggested anything you haven't heard before, or though of yourself. As the holder of over a dozen US patents, I know that virtually any "new idea" I come up with has been thought of before. Rather than disappointment, I see that as validation :)
EDIT: I found you at Connecticut Custom Airguns. I am sure people pester you for a job all the time. How many try to sell you product ideas, or do incidental consulting?
P;
Thanks for the message, you already have an answer. Think it over.
As far as the pistons you mention, I already make something like that (it''s called the Anti-Bounce Piston or ABP). We just have a different perception of the materials needed, problem is that they are expensive, LOL!. Tests and the few specimens out there validate the fact that they are most useful with a small plenum.
Anyway, thanks again for your communications and if I can be of further assistance, just drop me a line.
Keep well and shoot straight!
HM
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Well, if physics and a lack of the devil in the details allowed it, I'd want:
At least 20 fpe in .22 cal, 25 fpe in .25 cal would be even better but you say that's wishful thinking.
I wouldn't consider a .177 since I'd want this for hunting only. I'm not into competitive shooting.
A bullpup configuration with a side lever for cocking. I like the idea of a ratcheting cocking lever but don't know if its really necessary.
Somewhere around 7 pounds or less unscoped.
Fully shrouded barrel for sound suppression or at least a threaded barrel tip with 1/2-20 UNF threading.
Sling mounts and weaver mounts here and there.
A bubble level would be nice.
Oh yeah, and a compass. There needs to be a compass in the hilt. ::) 8)
I wouldn't want a stock with one of those deep/tall bellies in the forearm "for resting the rifle on the knee" like one of the previous posters had mentioned. There were many airguns I decided against buying because they had one of those exaggerated bellies. It makes it very difficult to shoot from a rest the way I do with one of those forearm bellies.
Seriously though, I've wondered about integrating shock absorbers into the stock. With a synthetic stock, the stock could be molded with the absorbers in place. What would work best for shock absorbing? I don't know. Thick hard rubber pads? Springs? Little pneumatic pistons? That way the barrel and action is supported by the shock absorbers which are in turn held by the stock. The barrel and action wouldn't actually be in contact with the stock. The shock absorbers would only allow the barrel and action to move in a straight line front and back. Kind of like how a howitzer works.
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I would probably have to have one. Would want 12fpe or more like many others have said!
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I would not.
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Thanks for your continued interest and replies!
All replies are useful.
In the little over 1 week we have been discussing this, there are now more than 5000 shows of interest, of which a little under 90, ended in a post, of which less than 10 are negatives.
Sure there are a lot of details to work out. And possibly we can come up with something that satisfies the majority. Because "you can't win'em all", it's just human nature.
One thing for sure is that we will try to avoid Whiscombe's errors. And our own past errors, also!
The technology and physics of the system are more than fascinating, and the new manufacturing technologies open so many doors.
We'll have a better feeling about whether this becomes a project or not after IWA (March).
Thanks again!
HM
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Thanks for your continued interest and replies!
All replies are useful.
In the little over 1 week we have been discussing this, there are now more than 5000 shows of interest, of which a little under 90, ended in a post, of which less than 10 are negatives.
Sure there are a lot of details to work out. And possibly we can come up with something that satisfies the majority. Because "you can't win'em all", it's just human nature.
One thing for sure is that we will try to avoid Whiscombe's errors. And our own past errors, also!
The technology and physics of the system are more than fascinating, and the new manufacturing technologies open so many doors.
We'll have a better feeling about whether this becomes a project or not after IWA (March).
Thanks again!
HM
Hector,
I will even put my money where my mouth is and give you/Diana a $100 deposit! ;) ;D ;) 8)
-Y
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Seriously though, I've wondered about integrating shock absorbers into the stock...
The shock absorbers would only allow the barrel and action to move in a straight line front and back. Kind of like how a howitzer works.
Tim,
This thread is about a spring air rifle that uses the Giss system. The Giss system has a mass of equal weight to the piston, that moves in coordinated manner, in the opposite direction of the piston at the instant of firing. This does a very good job of cancelling vibration and "recoil". Hence, no additional shock absorbers or other damping parts or materials would be required...
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Hector,
I will even put my money where my mouth is and give you/Diana a $100 deposit! ;) ;D ;) 8)
-Y
Thanks, Yogi!
I could take to IWA about $2000 in deposits of that amount if it was reasonable to do so.
But I cannot. I do however, understand your commitment and that of other friends here that have offered down payments on the rifle.
It is one of the "aces" I have to show the "powers that be" that it is a genuine way forward for the brand.
Again, thanks! It's been a true education for me.
Keep well and shoot straight!
HM
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I didn't think to mention in my first post that it needs to ambidextrous or available in a LH stock too.
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No!
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Seriously though, I've wondered about integrating shock absorbers into the stock...
The shock absorbers would only allow the barrel and action to move in a straight line front and back. Kind of like how a howitzer works.
Tim,
This thread is about a spring air rifle that uses the Giss system. The Giss system has a mass of equal weight to the piston, that moves in coordinated manner, in the opposite direction of the piston at the instant of firing. This does a very good job of cancelling vibration and "recoil". Hence, no additional shock absorbers or other damping parts or materials would be required...
Derp,
I know that.... Thanks for belittling me. Sorry that I went ahead and said something off topic that made you think I am stupid. When can I take the dunce cap off so that you can wear it?
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No one thought you were stupid, Tim. It appeared you had not read or understood the premise of the original post.
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So where did this project end up at?
Any report if it's going to happen or still in the design stage?
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I'm still hoping for a 54 synthetic stock. I believe I would get out the plastic doghouse card for that.
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I’d be interested in a D54 if there was a LH or ambi. OEM FT style stock available.
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Recoil-less Spring-Piston Airgun?
Ideas, comments, and pro-positive suggestions welcome.
TIA!
HM
Yes, if the gun can be kept in the 8.5lb. or less range ;).
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Nope, I'd rather have a new truck. ;D
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GOOD that we all keep our sense of humour.
At present we are examining all our options. Some projects are further along than others and have a higher probability of success, so they will get priority, some others are not urgent, but are important, and so, they will get done, just not straightaway.
I cannot give you a lot more details, but next year SHOT Show should be a very interesting year and IWA will see a lot of attention on notable improvements to the airgun technology.
Keep your fingers crossed and keep insisting on this.
;-)
HM
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soooooo... I have between _now_ and the SHOT show to save up?
Please keep us posted!!
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I'm looking forward to hearing more...
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Side lever. I prefer the unencumbered barrel of a side lever.
11-12fpe minimum.
I would be interested as it's similar to a project that I started but abandoned (technical difficulties). I used a single piston and a counter-mass (like a D75).
(http://www.scotthull.us/photos/Misc/SE001-00.jpg)
(http://www.scotthull.us/photos/Misc/SE001-01.jpg)
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Side lever. I prefer the unencumbered barrel of a side lever.
11-12fpe minimum.
I would be interested as it's similar to a project that I started but abandoned (technical difficulties). I used a single piston and a counter-mass (like a D75).
...
(http://www.scotthull.us/photos/Misc/SE001-01.jpg)
I think I'd drop the rack and pinion in favor of an aramid string/cable, e.g. spectra. Less noise and wear and tear. You might even be able to introduce some mechanical advantage to reduce the size of the counter-mass, e.g. use a pulley. The tricky part is to make it double acting to properly couple the two masses, especially when the active piston starts decelerating at the end of the stroke--you can't push a string. I think that would end up with a loop and a couple of idlers...it could get pretty weird.
Maybe let the counter-mass act on an air cushion at the end of its stroke as well, just to act as a brake? That may not have to be perfect to be effective.
Oh, or maybe replace the rack and pinion with band drives using aramid bands instead of metal bands. (Some old hard drives used this as a zero backlash method of moving the read heads with rotary stepper motor.)
Hmm...that might make a few of us crank up the simulations to see what kind of forces are acting the strings or racks or whatever coupling you come up with...
Is there an advantage of the Giss system over a sled system like the Diana 54?
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I would have an interest. Definitely would need to be a side Cocker. I don't shoot from a bench and less to Simply sight in the gun. Under lever and break barrel both require me to change my shooting position in order to cock the rifle side lever I can stay in my shooting position prone, sitting or standing.
I would be looking at a dual power design already suggested. Maybe short stroking the spring / gas piston. Possibly a multi cock design or appropriate valving of the second piston.
Personally, weight is not an issue for me. But I can see where can be for those smaller in stature. I think a realistic weight for something like this is going to be closer the 10 lb for Quality build and keeping the price point.
If it does come with sights I'd like to see the site moved from the middle of the rifle to the back of the receiver and offer a globe front sight.
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Side lever. I prefer the unencumbered barrel of a side lever.
11-12fpe minimum.
I would be interested as it's similar to a project that I started but abandoned (technical difficulties). I used a single piston and a counter-mass (like a D75).
...
(http://www.scotthull.us/photos/Misc/SE001-01.jpg)
I think I'd drop the rack and pinion in favor of an aramid string/cable, e.g. spectra. Less noise and wear and tear. You might even be able to introduce some mechanical advantage to reduce the size of the counter-mass, e.g. use a pulley. The tricky part is to make it double acting to properly couple the two masses, especially when the active piston starts decelerating at the end of the stroke--you can't push a string. I think that would end up with a loop and a couple of idlers...it could get pretty weird.
Maybe let the counter-mass act on an air cushion at the end of its stroke as well, just to act as a brake? That may not have to be perfect to be effective.
Oh, or maybe replace the rack and pinion with band drives using aramid bands instead of metal bands. (Some old hard drives used this as a zero backlash method of moving the read heads with rotary stepper motor.)
Hmm...that might make a few of us crank up the simulations to see what kind of forces are acting the strings or racks or whatever coupling you come up with...
Is there an advantage of the Giss system over a sled system like the Diana 54?
The single piston with counter-mass has some unique problems. The forces involved are a lot higher than you would at first think. The Diana 75 type mechanism was used in relatively low energy guns so it was doable. Even at 12fpe, the linkage system is problematic, though possible with the right manufacturing capability. On my design, I had designed one of the main parts of the rack/linkage to be carbon fiber but was not able to produce a satisfactory part. Everything else I came up with was too weak and/or too heavy. A true Giss system like the Whiscombe, uses two opposing pistons that are geared together. The two pistons see equal force so the gearing mostly synchronizes them. They see a lot lower stress.
On a single piston system with counter-mass, any additional cushion added to intercept the counter-mass steals energy that would otherwise have compressed the air and propelled the pellet - so efficiency suffers.
The sled system subjects the scopes to higher accelerations than a normal piston gun. There are work arounds like the Diana Bullseye mount. The Giss system does not stress the scope.
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Nope, I'd rather have a new truck. ;D
+2
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Interesting ideas, but the single acting piston has been discarded.
Reason is simple: If you want a swept volume with a minimum of size and weight, you need BOTH pistons to do work.
IF the currently existing Giss System rifles (DIANA 60, 65, 66 and 75) were of the "coming at each other" variety instead of the "going away from each other" variety we would already have 11 ft-lbs guns, just because the mass, spring force and swept volume actually doing work would double.
Not so sure about the side cocking, one of the ideas is to create a break-barrel with dual cocking levers, just that one would push and the other would pull.
The easiest embodiment is the underlever.
We'll see.
And if anyone thinks they can get a new truck for less than $1,000 . . . perhaps they are looking at different brands than what I am seeing.
;-)
HM
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Interesting ideas, but the single acting piston has been discarded.
Reason is simple: If you want a swept volume with a minimum of size and weight, you need BOTH pistons to do work.
IF the currently existing Giss System rifles (DIANA 60, 65, 66 and 75) were of the "coming at each other" variety instead of the "going away from each other" variety we would already have 11 ft-lbs guns, just because the mass, spring force and swept volume actually doing work would double.
Not so sure about the side cocking, one of the ideas is to create a break-barrel with dual cocking levers, just that one would push and the other would pull.
The easiest embodiment is the underlever.
We'll see.
And if anyone thinks they can get a new truck for less than $1,000 . . . perhaps they are looking at different brands than what I am seeing.
;-)
HM
"...If you want a swept volume with a minimum of size and weight, you need BOTH pistons to do work...."
+1
"...IF the currently existing Giss System rifles (DIANA 60, 65, 66 and 75) were of the "coming at each other" variety instead of the "going away from each other" variety we would already have 11 ft-lbs guns, just because the mass, spring force and swept volume actually doing work would double...."
The Giss System patent shows two pistons "coming at each other" and synchronized by a rack and pinion. The 60, 65, 66, and 75 have a single piston and a counter-mass "going away from each other". Though they too are synchronized by a rack and pinion, they do not appear to be a "Giss System". I don't know if they had there own patent, but they look like a unique system.
"Not so sure about the side cocking, one of the ideas is to create a break-barrel with dual cocking levers, just that one would push and the other would pull...."
There were some interesting build threads on the machine board a few years back. The designs had a dual piston that used a forward/backward sidelever. They had a simultaneous sear release though no other synchronizing mechanism.
The dual piston semi-bullpup configuration has some advantages.
https://www.gatewaytoairguns.org/GTA/index.php?topic=58977.msg568590#msg568590 (https://www.gatewaytoairguns.org/GTA/index.php?topic=58977.msg568590#msg568590)
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Scott;
Yes there are several Giss patents. Simply because Kurt Giss was one the head designers for DIANA after WWII.
The most interesting one for our modern purposes is # 2,938,513 under USPTO numbering of May 31, 1960, but there are patents going way back to 1956 with different variations.
The MAIN advantage of a semi-bullpup cofiguration is the simplification of the trigger system.
Interesting thread by American Airguns, and definitely on the right track. I wonder/ Do you know if a prototype ever got built?
Keep well and thanks!
HM
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Scott;
Yes there are several Giss patents. Simply because Kurt Giss was one the head designers for DIANA after WWII.
The most interesting one for our modern purposes is # 2,938,513 under USPTO numbering of May 31, 1960, but there are patents going way back to 1956 with different variations.
The MAIN advantage of a semi-bullpup cofiguration is the simplification of the trigger system.
Interesting thread by American Airguns, and definitely on the right track. I wonder/ Do you know if a prototype ever got built?
Keep well and thanks!
HM
He did build a prototype, but not the bullpup.
https://www.gatewaytoairguns.org/GTA/index.php?topic=25115.0 (https://www.gatewaytoairguns.org/GTA/index.php?topic=25115.0)
I guess the independent pistons balanced out well and did not require the rack and pinion for synchronization. The large bore diameter required heavy pistons. He never got the fpe that he was going for, but it was still over 12fpe.
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Thanks for the link, Scott!
As was evident from the result, as masterful as the embodiment was, it strayed too much from established parameters to work well.
I found particularly troubling the idea of charging gas springs to 1,200 and then 2.400 PSI for yields of 20 "ísh" ft-lbs. in 0.22" cal.
One of the projects we are working on right now as high priority tells me that you do not need more than 900 PSI / 62 BAR to reach 20 ft-lbs in 0.22"cal with less than 40 lbs of peak cocking force in a SINGLE piston architecture /135 degrees cocking arc, 30 mm's bore/100 mm's stroke. Working with double pistons, we should be able to keep the key numbers but by splitting the stroke the lock time should halve and recoil should go away.
Synchronizing pinions and racks are also vital to a good working gun in the long run.
Lots of really masterful machining in that thread, but totally unfeasible as an industrial product. Compliments to QV Tom, and thanks to you for the lesson!
Keep well and shoot straight!
HM
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Thanks for the link, Scott!
As was evident from the result, as masterful as the embodiment was, it strayed too much from established parameters to work well.
I found particularly troubling the idea of charging gas springs to 1,200 and then 2.400 PSI for yields of 20 "ísh" ft-lbs. in 0.22" cal.
One of the projects we are working on right now as high priority tells me that you do not need more than 900 PSI / 62 BAR to reach 20 ft-lbs in 0.22"cal with less than 40 lbs of peak cocking force in a SINGLE piston architecture /135 degrees cocking arc, 30 mm's bore/100 mm's stroke. Working with double pistons, we should be able to keep the key numbers but by splitting the stroke the lock time should halve and recoil should go away.
Synchronizing pinions and racks are also vital to a good working gun in the long run.
Lots of really masterful machining in that thread, but totally unfeasible as an industrial product. Compliments to QV Tom, and thanks to you for the lesson!
Keep well and shoot straight!
HM
Now about that truck...... :D
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...
I found particularly troubling the idea of charging gas springs to 1,200 and then 2.400 PSI for yields of 20 "ísh" ft-lbs. in 0.22" cal.
One of the projects we are working on right now as high priority tells me that you do not need more than 900 PSI / 62 BAR to reach 20 ft-lbs in 0.22"cal ...
...
Whether it needs 900psi or 1200psi to achieve a certain force would be a function of the shaft diameter. So either could work.
In a gas spring, the shaft cross section area x psi determines the force in pounds.
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...
I found particularly troubling the idea of charging gas springs to 1,200 and then 2.400 PSI for yields of 20 "ísh" ft-lbs. in 0.22" cal.
One of the projects we are working on right now as high priority tells me that you do not need more than 900 PSI / 62 BAR to reach 20 ft-lbs in 0.22"cal ...
...
Whether it needs 900psi or 1200psi to achieve a certain force would be a function of the shaft diameter. So either could work.
In a gas spring, the shaft cross section area x psi determines the force in pounds.
Yes and no.
Yes in the sense that in a perfect world the maths are "pure", once you get into the realities of tolerances, frictions (static and dynamic) and starting pressures in the gas spring hysteresis cycle, there are differences that can account for up to half of the energy returned. So you may need 1.5 times the input "work" to get the same returned energy.
Like in this case. IIUC, 2,300 PSI's returned barely 25 ft-lbs; 2.5 times the pressure for 25% more muzzle energy is too high a price to pay, IMHO.
Given the current technology, we know we can charge a gas spring to 4,500 PSI, but what good would that be if the gas spring so charged is not efficient, and above all impossible for a person to cock the action?
We also know that we can get 20 ft-lbs from a spring charged to 22 BAR, but again, that is also not a practical weight rifle because the stem is only part of the equation, there is a piston head at the end of the stem inside the cylinder.
Keep well and shoot straight!
HM
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I did quite a bit of research and experimenting with gas springs in piston guns. Though gas springs have some advantages, I now prefer wire springs for my target rifles.
Because of the likely trigger configuration, this new design could probably use either gas springs or wire springs.
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I did quite a bit of research and experimenting with gas springs in piston guns. Though gas springs have some advantages, I now prefer wire springs for my target rifles.
Because of the likely trigger configuration, this new design could probably use either gas springs or wire springs.
You are right. Steel springs are still more efficient.
For example, comparing exactly the same architecture and ONLY changing the nature of the spring, we need 25# of peak cocking force for a 12 ft-lbs yield, while only needing 20# of peak cocking force with a steel spring and an ABP device.
BUT, the quality of the shot cycle is so much superior using the gas spring that I deem it a worthwhile trade-off.
Let me put it this way:
If a "conventional" 34 kicks at 100, the ABP version kicks at 40, but the GasRam system kicks at 25.
We are looking at using just one trigger type for all guns, and that requires re-thinking EVERYTHING inside the guns.
That's what keeps me extremely busy and sometimes awake at nights, LOL!
As I said, SHOT and IWA 2020 are going to be VERY interesting.
😉
Keep well and shoot straight!
HM
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Hector,
Since you are rethinking “EVERYTHING” about the internals of a spring gun I was wondering what your thoughts are about friction reduction inside the compression chamber. I ask because for the most part the largest change in airgun design pertaining to friction reduction appears to be the use of moly for lubricants and use of self lubricating seals. Sadly, these improvements are often an aftermarket fix. Is DIANA considering any other friction reduction methods, such as coating the compression chamber, trigger sear, or piston contact points with something more advanced like Teflon? I have no clue about the cost vs. benefit, but thought it worth asking the question to gain more insight.
-Marty
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Marty,
My understanding is that as the air is compressed in front of the piston, the pressure rises to somewhere between 3,000-5,000 psi for just an instant. At these pressures, petroleum products easily vaporize and explode. Maybe a ceramic coating, like they use on the space shuttle would work? ;D
-Y
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Marty,
My understanding is that as the air is compressed in front of the piston, the pressure rises to somewhere between 3,000-5,000 psi for just an instant. At these pressures, petroleum products easily vaporize and explode. Maybe a ceramic coating, like they use on the space shuttle would work? ;D
-Y
Yes, the temperature gets very high for a thousandths of a second, but Teflon is a solid with a melting point of 600 K. My thinking was that there would not be enough time for the temperature spike to actually raise it to 600 K and vaporize the Teflon. Just to clarify, I am not advocating it’s use as a paste, but as a coating just like on a frying pan.
-Marty
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I'm a little late to the conversation but I think it would be an interesting idea. Kind of like the old Whiscombe and Park rifles but a lot cheaper! :)
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Hector,
Since you are rethinking “EVERYTHING” about the internals of a spring gun I was wondering what your thoughts are about friction reduction inside the compression chamber. I ask because for the most part the largest change in airgun design pertaining to friction reduction appears to be the use of moly for lubricants and use of self lubricating seals. Sadly, these improvements are often an aftermarket fix. Is DIANA considering any other friction reduction methods, such as coating the compression chamber, trigger sear, or piston contact points with something more advanced like Teflon? I have no clue about the cost vs. benefit, but thought it worth asking the question to gain more insight.
-Marty
Marty;
In a way, yes.
So far, my research tells me that there are things that truly add to the efficiency, and things that do not so much.
And it changes between Breakbarrels and Sliding Chamber guns.
For example the pistons:
The LGV and the 34/340 (when converted to Steel spring to regulate accurately the energy yield), benefit most from an Anti-Bounce Piston.
For the 430, 460, 48->56 models, the best is the ORing piston with Teflon riding rings and slippery sealing ORings.
Now, the problem with delivering "Formula 1" cars to "Sunday drivers" is that many consumers simply cannot be careful enough with all that power. So the gun dies.
And if you want to deliver guns that are "customer proof", then what exists is already as good as commercially possible.
That is the reason why I no longer sell the HMO Piston, and the ABP are sold only on an 'installed' basis. It is not fun to have to replace something that you KNOW was damaged in abuse (not use), and yet, it needs to be done, all in the name of upholding the brands (CCA as welll as DIANA).
There IS a way to achieve something sort of "halfway there", and we are looking into it. AAMoF, I am waiting on some piston BODIES to make some prototypes.
Whether DIANA will adopt the technology or not is a different story, but the technology will be there for them to see.
IF we can achieve a better/less expensive way of making the pistons, and at the same time, make them better, then we will have arguments for the adoption, if not, then this level of refinement will have to stay in the realm of the custom gunsmith catering to a discerning clientele.
A lot of you, and even the creator himself, have asked my why DIANA has not considered the reduced bore compression chamber. The truth is that we HAVE considered and found it inadequate in the countries where elevation differences between venues are larger than 1,000'.
The reduced compression chamber looses too much as the gun is brought to higher elevations.
Best solution here is a short-stroked piston. Again, something that needs to have a dual "ying-yang" argument for its adoption (less cost AND better performance).
And if we now talk of the springs: There are already springs that are Teflon coated and are wider in body diameter, so that they do not need the sleeve.
But some users, and even some "well respected tuners" descry that and refer to these as "springs almost too big for the piston". And I put this between quotes because I have the EMails to prove it. Of course I will not mention names, but we cannot risk that in a production unit.
The metallurgy of the springs has also changed. With so much of the world high-spec steel now being made in Japan, and less and less in Sweden and Germany, there is a clear vacuum of material advancement. But the Japanese companies that make the very specific steels for high-performance/long-endurance springs are not interested in the airgun business. Automotive deals of billions of dollars are what moves these companies, and so, even if the knowledge exists, it is impossible to apply.
Finally consider that the spring-piston airgun is becoming harder and harder to sell in a world where compressors are becoming cheaper and cheaper.
We do understand the appeal of the self-powered airgun, believe me; and so, we are looking at all possible avenues of innovation.
Sorry that I cannot give you a more detailed response, but most of this is work in progress.
Keep well and shoot straight!
HM
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Hector,
Thank you for providing the commercial perspective. Well explained as usual and encouragement for the gun smiths and tinkerers out there that enjoy innovating beyond the original factory specs/optimizations.
I myself like a good bang for the buck and simplicity, but there is also the other Jekyll & Hyde side of me that wants to wringout the last morsel of performance without regard for economics, just because it’s there.
Keep up the good work!
-Marty
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Thanks for your kind words, Marty, greatly appreciated.
Today I had a really good conversation with someone that is EXTREMELY knowledgeable about the US Market, and he was commenting that the "breakbarrels are dead".
Interesting statement and one that bears qualification:
He really meant the breakbarrels are not being sold in good numbers any more.
I thought that it would be sensible to use the 65 action as a model because being a breakbarrel it has less parts (less things to make and to fail), and the cost can be kept in line, but if I am interpreting correctly his figures on the market then, truly, the breakbarrels are destined to go the way of the dinosaurs.
In a way it makes sense, you have in the market the accumulated production of over 130 years of breakbarrels (minus attrition), still that means a LOT of breakbarrels, enough to satisfy the curiosity of anyone interested.
For sure there will always be the $100 breakbarrel, it's simply too much of an impulse buy temptation to NOT have it in a department store / super-center. But the high end gas piston/high quality breakbarrel of new manufacture seems to be destined to extinction.
And how long will it be till the fixed barrels also go that way? When presented in detail with the ideas we've been venting here in this thread, he conceded that a recoil-less, easy to shoot, autonomous, medium-to-high power airgun would have some appeal, he also commented that what he saw from the market was the need for better and less expensive compressors.
So, this conversation gives me food for thought. It raises the bar of performance to the point where it will not be easy to stay within the set MSRP
Anyway, the door is always open to ideas.
Again, thanks for your kind words. Keep well and shoot straight!
HM
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I find the talk of some kind of bull-pup configuration to be interesting. I'd really like to see a quality side-lever bull-pup whether single piston or GISS. I say quality because I know there's that Chinese one floating around out there but the quality isn't quite up there enough for me to get one.
I'm a small guy and its hard for me to shoot a rifle off-hand if it weighs more than 6 pounds. However, if its center of gravity was brought back at least behind the forearm (preferably over or just behind the trigger), it would be easier for me to shoot off-hand if it weighs a bit more. Otherwise, I'm shooting from a rest. Also, if I go hunting, its in dense brush/forest and a long gun is unwieldy is such conditions. Something shorter is much easier to handle.
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I find the talk of some kind of bull-pup configuration to be interesting. I'd really like to see a quality side-lever bull-pup whether single piston or GISS. I say quality because I know there's that Chinese one floating around out there but the quality isn't quite up there enough for me to get one.
I'm a small guy and its hard for me to shoot a rifle off-hand if it weighs more than 6 pounds. However, if its center of gravity was brought back at least behind the forearm (preferably over or just behind the trigger), it would be easier for me to shoot off-hand if it weighs a bit more. Otherwise, I'm shooting from a rest. Also, if I go hunting, its in dense brush/forest and a long gun is unwieldy is such conditions. Something shorter is much easier to handle.
Exactly, a kind of compact side lever Diana 54, with gasram, with an output of about 14-15 ft/lb and a bull barrel. Oh, and a weaver rail please !